Abstract: A brain activity determination device is equipped with a chaos index value calculation unit 201 for calculating a chaos index value, which is an index for determining the chaotic nature in chronologically ordered data; and a determination unit 205, which stores outputs obtained by inputting the RRI data obtained from a subject placed in a first state where the load on the brain is for obtaining reference value data, calculates an index value ratio that is a ratio of the reference value data and the chaos index value to be evaluated by inputting the RRI data obtained from a determination subject whose brain load is in a second state where evaluation target data is obtained to the chaos index value calculation unit 201 after obtaining the chaos index value to be evaluated, which is the data to be evaluated; and determines the brain activity state of the determination subject based on a comparison between the brain activity threshold and the index value ratio to determine the brain activity state.

Abstract: To achieve high accuracy and high processing speed, a time series data evaluation device is equipped with a probability calculation unit 201 that calculates the probability p(i) that ?t?Ai; a division entropy calculation unit 202 that calculates division entropy using the measure in the subdivision interval by setting a subdivision section Bi (i=1, 2, . . . , M×Q) by further dividing the divided section Ai (i=1, 2, . . . , M) into Q equal parts; and a summation calculation unit 203 that performs a summation calculation of the divided interval range regarding the multiplication of the probability p(i) and the division entropy.

Abstract: Encryption, having sufficient concealment, is carried out through chaotic computation using integer arithmetic. There is provided a cipher generating device, for carrying out computation, for plain text information, to apply chaotic noise obtained using a mapping function for generating chaotic noise based on encrypted key data, to generate a cipher. This cipher generation device comprises parameter generation means 102 for generating a parameter string for use in chaotic computation based on the key data, chaotic noise generating means 103 for carrying out chaotic computation using the parameter string generated by the parameter generating means 102 and obtaining the chaotic noise, and scheduling means 104 for carrying out scheduling of the parameter string so as to cause a change in the parameter string every fixed cycle the parameter string is used in the chaotic computation.

Abstract: Encryption, having sufficient concealment, is carried out through chaotic computation using integer arithmetic. There is provided a cipher generating device, for carrying out computation, for plain text information, to apply chaotic noise obtained using a mapping function for generating chaotic noise based on encrypted key data, to generate a cipher. This cipher generation device comprises parameter generation means 102 for generating a parameter string for use in chaotic computation based on the key data, chaotic noise generating means 103 for carrying out chaotic computation using the parameter string generated by the parameter generating means 102 and obtaining the chaotic noise, and scheduling means 104 for carrying out scheduling of the parameter string so as to cause a change in the parameter string every fixed cycle the parameter string is used in the chaotic computation.